Y do we keep such a fixed perception? It could be varied with experiences, thoughts, situations by people and time. The following thesis is to explore the realm of expansible space with the discrepancy between human cognition and perception.By way of defining simultaneous spatial relationships among space, object and human being,I set artificial circumstance with the form of furniture. x ; dots x, y ; lines x, y, z ; volume as space (x, y, z) + time These x, y, z and time are the basic elements to represent the world we live in. As a starting point, I progressively transform a form structured by x, y and z between negative and positive information physically and conceptually using materials. From a formal experiment, I discover details of a form that are easily ignored under human being''s assumption. To remind a viewer overlooked information of a form, I enlarge its scale twice but hide other information. In the next step, I leave minimum components that are capable to imply space, and eliminate redundant lines and planes. As the last step, I add one more dimension, ‘time'' to explain a personal relationship with object and space.